Contractor Talk - Professional Construction and Remodeling Forum banner
Cancel
Create thread New Forums

TELSTA A28D Bucket controls acting up

Jump to Latest
72K views 32 replies 19 participants last post by  50deuce85  
O
#1 ·
Hello everyone and thank you for allowing me to visit your forums.

Recently I purchased a 1994 F-450 with a A28D Bucket on the back for the purpose of changing out light fixtures (under canopy / light poles) at my customers locations. Problem I'm having with my truck is that the controls on the boom are acting up intermittently. The controls down low in the right rear panel all work fine. The truck came with the complete TELSTA owners / service manual which includes a complete wiring schematic, but I'm still lost of where I should start.

Anyways, I was hoping to pick the brains of the guys that work on these trucks and maybe they will be able to steer me in the correct direction. I'm hoping that this is a common issue and that there is a common fix.

Thank you in advance for any and all help that is sent my way...
 
O
#4 ·
Lon's Electric said:
Any luck finding those wiring diagrams?
Click to expand...
I have a complete set of manuals which includes wiring schematics. I am a NIASE (I'm dating myself) certified mechanic and an accomplished Experimental aircraft builder, but these wiring flow charts for this truck are enough to make you drink. Anyways, I believe I found the problem. Looks as if a couple of the spade connectors in the main control box are compromised. I'll be taking digital photos of the connections and then systematically replacing all the connectors 1-by1. Must be over 100 in this box.
 
P
#7 ·
a28d

We recently purchased a 2000 e350 with the Telsta A28D lift and had similar problems. Ours acted up when running the emergency 12v pump. I would have full control at the bottom in emergency, but only half at the top. If the van was running or if a charger were connected I would have no issue's as voltage was up. The problem was too much resistance in the wire that connected to the basket control override switch at the lower control box. Power had to run from the tower to the rear controls then back to the tower up the boom to upper controls and back down to the tower. the fix was installing a relay in the tower control box to eliminate the long wire run ( I can explain in more detail if needed). I am now not worried if I need to run the lift on the emergency pump. Problem solved...
 
P
#14 ·
Relay

You will need to find the wire in the tower that has power when the override switch is in normal posistion. This wire sends power up to your controls in the bucket. Due to power required to operate the solenoids when battery voltage is low as in emergency operation with 12v hyd pump running voltage drops to low for solenoids to function. This is caused by the resistance in the common power wire running from the tower to the rear of the van then back to the tower and up to the controls back down to the solenoids. By adding the relay in the tower you eliminate the resistance in the override circuit that causes the voltage drop. The relay will close upon the override switch activating, then the power circuit will be switched in the tower. You will have to meter this out and have electrical knowledge for this to work. I am assuming you have the a28d mounted on a van with the controls on the rear door if your having this voltage /control issue at the basket.
 
W
#29 ·
personal said:
Relay

You will need to find the wire in the tower that has power when the override switch is in normal posistion. This wire sends power up to your controls in the bucket. Due to power required to operate the solenoids when battery voltage is low as in emergency operation with 12v hyd pump running voltage drops to low for solenoids to function. This is caused by the resistance in the common power wire running from the tower to the rear of the van then back to the tower and up to the controls back down to the solenoids. By adding the relay in the tower you eliminate the resistance in the override circuit that causes the voltage drop. The relay will close upon the override switch activating, then the power circuit will be switched in the tower. You will have to meter this out and have electrical knowledge for this to work. I am assuming you have the a28d mounted on a van with the controls on the rear door if your having this voltage /control issue at the basket.
Click to expand...
That is what is going on... but I am no electrician. Is there a way for you to dumb it down for me?
 
P
#15 ·
a28d telsta

Yes hello, personal Thanks for the info I have a 94 f-450 and a telsta work box but am noticing the same tower box and located power and note that i have aswitch in cab that opens to 13.5 , so i will take the advice and run a normally closed relay for only upper and then when ineed power and lower ill switch to close lower and open upper Thanks.:thumbsup:
 
W
#19 ·
Hello, I just decided to get me a bucket truck , a 97 Ford with Telsta A28D, was wanting to see if someone could tell me where to get some user and wiring /service manuals for this unit. Also, I have already discovered an issue with it. It has Onan 4500 gen w/ battery for emergency back-up use- Unit starts fine from gen. or at back panel and the controls operate bucket smoothly but when you flip switch from override to normal to be able to contol from bucket ,it kills generator. Any ideas?? Thanks, WM.
 
J
#22 ·
Can anyone send me pics of the 3 relays wiring on inside of gen housing. Pls. It's a a28d telsa with Onan gen. I have from lift controls. A red, black with Xtra leg so 2 blacks ik it's constant 12v+. I have a white and green. Green has 5 legs total it's ground. From gen plug. I have 3 wires. Black, yellow start and a brown stop. But I can't figure how to wire them back on the three 5 prong relays
 
J
#23 ·
Can anyone send me pics of the 3 relays wiring on inside of gen housing. Pls. It's a a28d telsa with Onan gen. I have from lift controls. A red, black with Xtra leg so 2 blacks ik it's constant 12v+. I have a white and green. Green has 5 legs total it's ground. From gen plug. I have 3 wires. Black, yellow start and a brown stop. But I can't figure how to wire them back on the three 5 prong relays
 
J
#24 ·
Hey guys new here! So my neighbor has 02 e350 with a28d lift cmm Onan 5.5 or 4.5 tag is gone but anyways. I had to change his belt on bottom of the gen. Well my smart self thought by putting elect tape around the 3 relays in gen housing would keep wires where they were. Well nope few of them came off. Long story short I decided to one of my smartest moves of all time removed all the wires bcuz I couldn't get the few that came lose n right spots. So after removing all them I thought no big deal. Well if I couldn't figure 3 wires WTH did I think I could figure out 12 connections. Anyways could some pls send me either pics or tell me how to jump the relays correctly. I have 5grn grounds 1red 1white 2black12+ and off gen pigtail I have yellow {start} brown {stop} and black {switched 12+}I have the schematics but hard to read n follow I don't know if they even contain the info I need thanks to anyone who can help me. I got to get this thing going asap he needs it bad and I have been working on it far to long
 
This post has been deleted
Contractor Talk - Professional Construction and Remodeling Forum
posts
3.6M
members
170K
Since
2003
A forum community dedicated to professional construction and remodeling contractors. Come join the discussion about the industry, trades, safety, projects, finishing, tools, machinery, styles, scales, reviews, accessories, classifieds, and more!
Full Forum Listing
Explore Our Forums
General Discussion Tools & Equipment Business Painting & Finish Work Decks & Fencing